A sudden or important change or improvement. That brand-new shopping center is a quantum jump from the old, run-down mall that used to be in that location.
a very important improvement or development in something (often + forward ) The election of a female president is a quantum leap forward for sexual equality. (often + from ) The food at Rockresorts is a quantum jump from the meals served at most Caribbean resorts.
A dramatic advance, especially in knowledge or method, as in Establishing a central bank represents a quantum leap in this small country's development. This term originated as quantum jump in the mid-1900s in physics, where it denotes a sudden change from one energy state to another within an atom. Within a decade it was transferred to other advances, not necessarily sudden but very important ones.